qubit

noun

qu·​bit ˈkyü-bət 

plural qubits

: a unit of computing information that is represented by a state of an atom or elementary particle (such as the spin) and can store multiple values at once due to the principles of quantum mechanics

And the most basic truth of quantum mechanics dictates that you cannot measure a qubit without destroying the superposition. The register that said 1 and 0 will randomly collapse into 1 or 0.

—George Johnson

compare bit entry 3 sense 1

Examples of qubit in a Sentence

Recent Examples on the Web

Data is held in qubits (quantum bits), which could hold all possible states simultaneously. —Chuck Brooks, Forbes, 24 Dec. 2024

Taqi Raza, assistant professor of electrical and computer engineering at the University of Massachusetts Amherst, said existing cryptos will have to evolve to ward off qubits. —Kevin Williams, CNBC, 22 Dec. 2024

Traditionally, adding more qubits increases the likelihood of errors. —Gordon G. Chang, Newsweek, 11 Dec. 2024

But many qubits are also needed to correct the errors that come from the noise of combining many qubits — a key hurdle for quantum computers. —Alison Snyder, Axios, 9 Dec. 2024

Word History

Etymology

qu- (in quantum entry 2) + bit entry 4, probably formed with punning allusion to cubit

Note: According to the American physicist Benjamin Schumacher, in the acknowledgements to a paper ("Quantum coding," Physical Review A, vol. 51, issue 4 [April, 1995], p. 2747), "The term 'qubit' was coined in jest during one of the author's many intriguing and valuable conversations with W. K. Wootters, and became the initial impetus for this work."

First Known Use

1994, in the meaning defined above